September 27, 2012
Astronomers Describe Energy Bursts Like Fireworks In The Early Universe
Lee Rannals for redOrbit.com — Your Universe Online
Astronomers suggest, in the Astrophysical Journal Letters, as galaxies formed in the early universe, they were accompanied by fireworks in the form of energy bursts.
Active galaxies are easily detected due to their luminous radio, ultraviolet or X-ray radiation, which results from steady accretion onto their massive central black holes.
Little has been known about the composition of these galaxies or their relationship to the normal galaxy population. However, ESA's Herschel Space Telescope helped to add more light on the active cosmic neighborhoods.
Herschel is larger than NASA's Hubble and operates at far-infrared wavelengths, which enables it to detect heat radiation generated by the processes involved in the formation of stars and planets.
The astronomers gave a detailed analysis of the first three distant radio galaxies observed using the Herschel telescope.
The fact that these objects emit strong far-infrared radiation indicates that vigorous star formation is taking place in their galaxies, which creates hundreds of stars per year.
The astronomers wrote that the bright radio emission implies strong simultaneous black hole accretion. This means that while the black holes in the centers of the galaxies are growing, the host galaxies are also growing rapidly.
The observations made by the team provide an explanation for the observation that more massive galaxies have more massive black holes.
Astronomers have been observing this scaling relationship since the 1990's, when they theorized fireworks in the early universe could be responsible for this relationship.
Our Milky Way galaxy forms stars at a slow pace, with an average of one new star a year being born. Our galaxy contains about a hundred billion stars, so the changes within the galaxy are very slight.
"It is becoming clear that active galaxies are not only among the largest, most distant, most powerful and most spectacular objects in the universe, but also among the most important objects; many if not all massive normal galaxies must also have gone through similar phases of simultaneous black hole-driven activity and star formation," Peter Barthel of the Kapteyn Institute of the University of Groningen in the Netherlands, who led the research, said in a statement.